Abstract
We report on the discovery of K2-141 b (EPIC 246393474 b), an ultra-short-period super-Earth on a 6.7 h orbit transiting an active K7 V star based on data from K2 campaign 12. We confirmed the planet's existence and measured its mass with a series of follow-up observations: seeing-limited Muscat imaging, NESSI high-resolution speckle observations, and FIES and HARPS high-precision radial-velocity monitoring. K2-141 b has a mass of 5.31 ± 0.46 M⊗ and radius of 1.54-0.09+0.10 R⊗, yielding a mean density of 8.00-1.45+1.83 g cm-3 and suggesting a rocky-iron composition. Models indicate that iron cannot exceed ∼70% of the total mass. With an orbital period of only 6.7 h, K2-141 b is the shortest-period planet known to date with a precisely determined mass.
Original language | English (US) |
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Article number | A95 |
Journal | Astronomy and Astrophysics |
Volume | 612 |
DOIs | |
State | Published - Apr 1 2018 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- Planetary systems
- Planets and satellites: individual: EPIC 246393474 b
- Stars: fundamental parameters
- Stars: individual: EPIC 246393474
- Techniques: photometric
- Techniques: radial velocities